Carnot 3BCAR

Bioeconomy, what's new in Science?: The controlled synthesis of oligosaccharides and biosurfactants from sucrose by the engineering of bacterial enzymes

Over the past decades, non-digestible carbohydrates have gained considerable attention for their health-promoting benefits, especially through their modulatory effect on the gut microbiota. Synthesis of new structures is of primary interest to provide new generations of functional products and better understand their effects. In parallel, environmental and sustainability concerns push forward the research on renewable and recyclable surfactants with well-defined and highly reproducible structures in order to replace the petroleum-based products.

Working in the field of glycobiology, our group has a long-standing interest in enzymes from Lactic Acid Bacteria (α-transglucosylases from GH70 family) that use sucrose as sole substrate for the synthesis of a variety of α-glucans (polysaccharides of glucosyl units). With the progress in bioinformatics, structure-function studies, screening technologies and enzyme engineering, new alpha-transglucosylases were recently discovered and further tailored to produce innovative biosourced compounds.

This presentation will first briefly focus on the structure-function relationship studies of these intriguing enzymes, aiming at better understanding the determinants responsible for linkage specificity or polymer size. These findings open promising strategies for enzyme engineering aiming at customizing α-glucan architectures on purpose. For illustration, recent developments for the synthesis of glucooligosaccharides rich in α-1,6; α-1,2 and/or α-1,3 osidic linkages will be shown, as well as the design of eco-friendly processes for the production of new alkyl-polyglucosides.